Fuses



M. SCHWEER July 24, 1962 FUSES Filed March 4, 1958 n m n m .1

MAX SCHWEE R JOQM ATTORNEYS atent Ufiice 3,046,373 Patented July 24, 1962 3,046,373 FUSES Max Schweer, Lindenstrasse 40, Ncumunster,

Filed Mar. 4, 1958, Ser. No. 719,016 Claims priority, application Germany Mar. 5, 1957 3 Claims. ((31. 200-121) errnany mounted on the fuse element supported by the fuse.

carrier. In one type of the known fuses the contact blades are so mounted on the fuse element as to extend along and beyond the elongated fuse element in a longitudinal direction and they are fixedly connected with the front plates of the fuse element.

In another type of fuses, particularly those fuses having extremely small dimensions, the contact blades and the receiving contact pieces are positioned transversely relative to the longitudinal extension of the fuse element.

These known constructions are unsatisfactory as they as they do not allow for an uncomplicated and accurate adjustment of the fuse element bearing the contact blades relative to the fuse carrier bearing the receiving contacts, although this adjustment is extremely necessary and highly desirable for the following reason. The body portions of the fuse elements and the fuse carrier are generally composed of ceramic material and it is impossible to produce the parts with the necessaryaccuracy and a minimum tolerance and consequently it is very difficult to accurately adjust the position of the contact blades of the fuse element and the receiving contacts of the fuse cam'er. Frequently it is necessary to adjust at least one end or one front plate of the fuse element to assume the exact position relative to the fuse carrier; this becomes necessary, for example, if the indicator button of the fuse is to be retained in a predetermined position in which it can actuate a releasing device as soon as the fuse responds to an excessive load in the circuit. For instance, it has been proposed to equip the fuse with a very small switch mounted at the lower portion of the fuse and operated by the indicator button of the fuse. Difficulty is experienced, however, in transmitting the movement from the indicator button to this very small switch, as a very bulky and comparatively voluminous construction of the fuse results if the switch is directly provided on the fuse element.

It will also be found desirable to transmit the movement of the indicator button via a control device directly to the releasing member of a switch, It will be necessary to provide particular and complicated control means compensating inaccuracies resulting from the unavoidable high tolerance of the fitting between the ceramic portions of the fuse, or otherwise to accurately position by hand the fuse element in an accurate position. This is, however, difficult if not impossible.

It is therefore an object of the present invention to provide a fuse with contact blades mounted at the ends of the fuse element and corresponding receiving contacts mounted on the fuse carrier, whereby a yery accurate adjustment of the fuse element relative tothe fuse carrier is automatically and easily effected when inserting the contact blades mounted on the fuse element into the receiving contact mounted on the fuse carrier, particularly taking into consideration the necessary accurate position of an indicator button relative to an actuating member operating, for example, a small switch.

This object is achieved by the fuse of the present invention in which one contact blade or its carrier has guide portions meeting fixed guide portions, for example at the fuse carrier, so as to accurately position the corresponding front portion of the fuse element in a predetermined transverse plane relative to the longitudinal extension of the fuse.

For example, one of the two contact blades mounted on the fuse element and the corresponding receiving contact mounted on the fuse carrier extend transversely relative of the longitudinal extension of the fuse, whereas the other contact blade mounted on the fuse element and the corresponding receiving contact mounted on the fuse carrier extend in the direction of the longitudinal extension of the fuse.

The present invention will be better understood upon the following description of the accompanying drawings, wherein:

FIGURE 1 is a side view of a fuse element with the contact blade of the present invention;

FiGURE 2 is a front view of the fuse element with the contact blade shown in FIGURE 1;

FIGURE 3 is a side view of another embodiment of the fuse element with the contact blade of the present invention;

FIGURE 4 is a fractional side view of still another embodiment of the fuse element with the transversely disposed contact blade of the present invention;

FIGURE 5 is a fractional side view of a modification of the embodiment shown in FIGURE 4.

Referring now to the drawings somewhat more in detail, FIGURE 1 shows a fuse element of a fuse of the present invention comprising the body portion composed of ceramic material 1 and the front plates 2 fastened to the ceramic body portion by screws 4, with the front plates 2 having protrusions 3 adapted to receive an operat-. ing handle. The first contact blade 5 extends in longitudinal direction relative to the extension of the fuse element, whereas the contact blade 7 extends transversely thereto. The contact blades can be provided with embossments 6 which can be used to harden the surface on the blade after performing a soldering operation or similar thermal processes. The same fuse element is shown in FIGURE 2, in another view, which also shows schematically the indicator button 15. As will be seen from FIGURES l and 2, the transversely disposed contact blade is provided on the same side of the fuse element on which there is arranged the indicator button 15.

According to another embodiment of the invention the transversely disposed contact blade and the corresponding front plates are formed of one integral piece of material. This is shown in FIGURE 3, in which the transversely disposed contact blade 8 constitutes an elongation of front plate 2a. The cross section of the contact blade 8 is reinforced by ribs as at 9. The receiving contact 10 forms one integral piece with terminal end 11 and is also transversely disposed relative to the longitudinal extension of the fuse. The indicator button 12 is disposed on the same side of the fuse bearing the transversely disposed contact blade just as the indicator button E5 in the embodiment shown in FIGURES l and 2. In front of the indicator button 12 there is provided an actuating member 13 having a contact spot 13a facing the indicator button 12. As soon as the fuse responds to a predetermined overload the resiliently mounted indicator button 12 is projected in a manner known per se against the contact spot 13a thus actuating the member 13 which, in turn, closes a contact device or releases a switch associated with the fuse. The resilient means actuating the indicator button 12 in a manner known per se can be easily adapted to provide sui'licient energy to effect the desired switching, by choosing a somewhat stronger than ordinarily used spring.

The front plate 2 of the fuse element and hence the indicator button 12 are very accurately adjusted and faithfully maintained in this adjusted position relative to the actuating member 13 by the snug engagement of contact blade 8 and the receiving contact 19.

It will be considered of advantage to use constructional elements of the fuse carrier which are substantially identical to conventionally used parts. This is made possible by so devising the contact blades that they are disposed at substantially the same height (see FIGURES 4 and 5). For this purpose, the transversely disposed contact blade 7 shown in FIGURE 4 forms one integral piece with the front plate 2 and is twice bent by an angle of 99 so as to assume a U-shaped configuration. The free end 17 of the contact blade 7 is sharply bent by 180 and the contact blade thus has a reinforced cross section. As this arrangement of the transversely disposed contact blade would cover and conceal the indicator button 15, the blade is provided with a window portion as at 14, through which the indicator button 1.5 can be observed.

Instead of twice bending the contact blade 7 as shown in FIGURE 4, it can be attached to the front plate 2 somewhat above the center of the latter (see FIGURE 5 Thereby, the transversely disposed contact blade is again situated at about the same height as the longitudinally arranged contact olade opposite to blade 7. The contact blade 7 is reinforced by ribs 16.

The novel construction of the present invention can be easily produced from constructional parts used in known fuses. For example, the transversely disposed contact blade 7 may be formed of a blade corresponding to the longitudinally disposed contact blade, which is, however, bent by an angle of 90. The flat portion 18 may be situated in the same plane or in a plane parallel to the plane in which there is situated the longitudinally disposed contact blade 5, with the portion 7 constituting the contact blade being bent so as to be transversely disposed relative to the longitudinal extension of the fuse.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What I claim is: v

l. A fuse comprising a fuse element, a first and second front plate mounted at opposite sides of said fuse element, an indicator button mounted in one of said front plates, at first contact blade lying in a plane parallel to the direction of longitudinal extension of said fuse element, and a second contact blade lying in a plane transerse to the longitudinal extension of said fuse element, said second contact blade and one of said front plates forming one integral piece and said second contact blade having a window allowing for observation of said indi- Cato-r button.

2. A fuse as described in claim 1, said second contact blade being disposed on that side of said fuse element bearing said indicator button.

3. A fuse comprising a fuse element; a first and a second front plate mounted at opposite sides of said fuse element in parallel relationship and transversely to the of said fuse element; a first contact blade integral with said first front plate and lying in a plane which includes said axis; a second contact blade integral with said second front plate and lying in a plane parallel to said second front plate and transversely to said axis; and an indicator button movably positioned in one of said front plates, said button moving in axial direction when said fuse elements respond to overload.

References Cited in the file of this patent UNITED STATES PATENTS 738,874 Baby Sept. 15, 1903 850,836 Hornsby et a1 Apr. 16, 1907 1,275,391 Cole Aug. 13, 1918 2,761,932 Kozacka et .al. Sept. 4, 1956 2,800,556 Swain et al. July 23, 1957 FOREIGN PATENTS 428,482 Great Britain May 14, 1935 

